The invention relates to electrical eyelet terminals of the type which are bolted to a mounting member in order to provide electrical continuity between a conductor attached to the terminal and the mounting member.
Eyelet terminals are used to secure an electrical wire to a mounting member such as a grounding surface or some other component of an electrical circuit. A conventional eyelet terminal is a generally flat, circular piece of electrically conductive metal with a stem to which the wire is crimped, soldered or otherwise permanently secured, and a central aperture for receiving a bolt. The bolt is inserted through the aperture and driven into engagement with a female threaded portion of the mounting member. The bolting operation is typically performed manually and requires the person performing the assembly to control at least three items: the terminal, the bolt, and the tool used to drive the bolt. To reduce the likelihood that the bolt may fall out of connection with the eyelet before it is driven into engagement with the mounting member, it is known to design the eyelet terminal so that it holds the bolt rotatably captive within the aperture. This is commonly achieved by forming small tabs or arms extending radially inward from the inner edge of the aperture to engage an unthreaded portion of the bolt shank immediately below the bolt head. An eyelet terminal with means for holding a bolt captive therein is disclosed in U.S. Pat. No. 5,863,227.
Even with the bolt held captive in the eyelet terminal, fastening the terminal to the mounting member requires the assembler to use two hands: one to hold and position the bolt/terminal combination over the bolt receiving hole in the mounting 25 member, and the other to hold and operate the bolt driving tool. This may be difficult or impossible to achieve if the terminal must be installed in a space-limited area. Even if there is room for a two-handed assembly operation, once the assembler begins to tighten the bolt the eyelet terminal may tend to rotate with respect to the mounting member, causing the wire attached to the terminal to become twisted, improperly routed, or subjected to undesirable tension.
The invention is an eyelet terminal that captures a bolt and is engageable with a mounting member to pre-position the terminal and bolt prior to the bolt being driven into engagement with the mounting member.
In the illustrative embodiment of the invention disclosed herein, an eyelet terminal has two generally circular eyelets in a spaced apart and generally parallel relationship with respective apertures in coaxial alignment. The first eyelet has a plurality of circumferentially spaced tabs projecting radially inward into its aperture to engage the bolt immediately adjacent the bolt head and retain the bolt in connection with the terminal. The second eyelet has retainer prongs extending toward the mounting member.
The bolt is held captive by the terminal so that the bolt head is adjacent the first eyelet and the shank passes through both eyelet apertures. The retainer is inserted into engagement with a first hole in the mounting member so that the second eyelet is adjacent the mounting member and the bolt is aligned with a second hole in the mounting member. This attachment of the terminal to the mounting member may be accomplished using only one hand and results in the bolt being held in a pre-set position from which it may be driven into engagement with female threaded means on the mounting member. As the bolt is driven into engagement with the mounting member, the spacing member deforms as the first eyelet is urged toward the second eyelet.
According to another feature of the invention, the first and second eyelets are spaced apart by a distance such that when the bolt is captive in the first eyelet and the retainer is engaged with the mounting member, the bolt is maintained in a pre-set position wherein the distal end of the threaded portion of the bolt shank is proximate a female threaded portion of the mounting member. In this pre-set position, the bolt is on the verge of engagement with the female threaded portion so that rotation of the bolt causes it to immediately begin to engage the female threaded portion.
According to a further feature of the invention, a spacing member comprising a curved section connects the eyelets and has a radius of curvature greater than one half of the distance separating the first and second eyelets. This large radius curve allows the spacing member to deform easily when the first eyelet is urged toward the second eyelet as the bolt is driven into engagement with the mounting member.
According to a further feature of the invention, a first retainer prong is relatively narrow so that it is flexible and a second retainer prong is wider and more rigid. The first prong is flexible so that it can deflect to allow the prongs to be urged through a slot in the mounting member. The second retainer prong is on the proper side of the terminal so that it is urged into contact with the edge of the slot when the terminal tends to rotate as the bolt is tightened, and is strong enough to resist the resulting force without deforming significantly.
Other objects, advantages and applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.